Clamshell bucket



y 1931- G. F. THOMPSON CLAMSHELL BUCKET Original Filed June 26, 1928 2 Sheets-Sheet 1 VA T TORNE YS.

May 19, 1931,, G F. THOMPSON CLAMSHELL BUCKET Original Filed June 26, 1928 2 Sheets-Sheet 2 INVE OR.

BY 77 KM ATTORNEYS.

partly in section. I

1 Patented May 19, 1931 UNITED S T PATENT, or'FIc I GEORGE F. THOMPSQN, or ERIE, PENNSYLVANIA,lASSIGNOR TO G. HQWILLIAMS COM- PANY, OF ERIE, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA CLAMSHELL BUoirE'r Application filed June 26, 1928, Serial No. 288,363. "Renewed lanuary 30, 1931.

Clam shell buckets are usually provided with a head and this is subjected to very severe duty. It is desirable to maintain 1t as of light construction as possible so as to keep the center of gravity on the bucket as a whole .as low as possible.

7 to receive the strains to which it issubjected.

to In the present invention this head is formed improvement in the latch mechanism Whereby the latch may be adj usted to remain looked under load and to automatically release as the load is released. Other features and details will appear more fully from the specification and claims.

A preferred embodiment ofthe lIlVBlltlOll is illustrated in the accompanying drawings as follows v 7 Fig. 1 shows a side elevation of the bucket,

Fig. 2 an endview of the bucket.

' Fig. 3 a section on theline33 in Fig. fl.

Fig. 1 a side view of the head. 1 and 2 mark the bucket members.v These are provided with arms 3 and 4 respectively and these are pivotally connected by a hinge pin 5. Links 6 are pivotally connected with. the bucket member .2 by a pin .7. The links are riveted to a head 8. Links 9 are pivotally connected by a pin 10 with the bucket member 1 and pivot'ally connectedtoithe head by a pin 106:. A catch blockll is secured on the pin 5 and to the arms 4. This block has a catch shoulder 12 which is adapted to engage a latch 13. I The latch 13 is pivotally mounted on apin 13a arranged'between the sides of a power arm 14', the power arm being pivotally'mounted on the pin 7 Aremov able cam, or wearing plate 16 is mounted in the end of the latch plate and has a cam surface 160; engaging a roller 17 on the triplever 18. The trip lever 18 extends from a trip" block 19 ournaled on a pin 20 extending between the sidesof the power arm 14. A trip arm 21 extends from the block 19 and may With the head of rigidity 1 and shaped to receive its several parts the bucket may be inade'of greater stlii ness so as be manually operated byatrip line 22, the

spring 25 is mounted on the trip arm -21 and is carriedagainst a pad 26 mounted on a pad arm 27 extending from the head 8 The trip block hasa positioning arm 28 with a roller 29 at its end which engages a plate 30, as the arm'is swung to place, thus throwingthe trip arm 18 outof the path ofthe cam block 16 sofas to permitof the latch 13 hooking over the shoulder 12 with the bucket open and the arm swung down to position; this latch operating in the'ordinary manner of such latches in buckets of this type. A stop 31 is also provided on the arm 28 which engages a stop 32 extending between'the sides of the arm 14.

This'stop limits the movement of the trip arm. 7 1 i The hookshoulder or the latch 12 is so designed that ittends to 'unhookjunder the load pressure and this unhooking is prevented by ready release is one of considerable nicety and the removable cam block 16 provides a means for mamtannng this surface in its proper re lation. As a further element in adjusting this means a set screw 33 is provided which extends though the arm 21 against the stop 32. By means of this set screw the position of the roller 17 onfthe cam'surface 16a may be nicely adjusted.

In the operation of the device with the bucket in open position, the power arm is dropped down and the latch set, this operatiug in the usual manner... As the bucket is lifted and thus closed, pressure is placed on the latchl2 and this operating through the cam surface 16a on the trip 18 holds the trip 18 in position. As the bucket is closed, it places the spring 25 under. tension, the force of the spring, however,- being insuflicient to force a tripping action ofthe trip arm so long as the load is on the latch, the cam surface being so'designed to operate under the and release the latch so that when the bucket is again lifted. it will open and discharge its contents. The bucket is operated from a single operating bridge through the duplicate lines 34. The lines 34 operate over guide sheaves 36 on the power arm, sheaves 37 on the power arm, sheaves 38 on the head, sheaves 39 on the arm, and sheaves 40 on the arm and are secured on the block 11 by a clamp 41. A buffer stop 42 is arranged on the arm and this engages a head 43 carried by a sliding pin 44, the pin sliding through an opening 45 on the head and being yieldingly heldin positionby a spring 46. Nuts 47 at the outer end otthe pin prevent its removal from the opening 45. This cushions the arm as it is brought up against the head.

The sheaves 38am journaled on a pin 38a and the head 8 has pockets 8a formed in the sides thereof which receive the sheaves 88. The inner walls of these pockets are connected by a central block and the outer walls extend downwardly over the sheaves forming a housing for the sheaves and a webbing for strengthening the head. The pins 38a extend through the central block and outer walls of the pocket. The outer walls of the pocket not only form a bracing and housing for the sheaves but also a means for securing the links 6 and 9 to the head. This head is formed of one casting and this makes it feasible to connect the central block rigidly with the outer walls 86 and thus make a rigid connection between the fixed links 6. This gives to the entire structure rigidity. The central block forms a convenient position for the pad 27 and also for the buffer structure which is mounted on the central block. In this way the part of the bucket which is subjected to the greatest strain is given this added rigidity due to its integral structure, simplifies the forn'iing of the housing and webbing of the head around the sheaves, and also a structi'lre capable of taking the incident to the butl'er structure.

What I claim as new is 1. In a clam shell bucket, the combination of bucket members; an integral head having a central block, sheave receiving pockets, and a sheave pin opening extending through the central block and the outer walls of the pockets; links pivotally connected to one of the bucket members and pivotally connected to the head; links pivotally connected to the other bucket member and rigidly secured to the head; sheaves in said pocket of the head; a sheave 'pin in the opening in the head on which the sheaves are mounted; and operating cables operating on said sheaves.

2. In a clam shell bucket, the combination of bucket members; a pivotal connection for said members; an integral head having a central block; sheave-receiving pockets and a sheave pin opening extending through the central block and the outer Walls of the pocket; links pivotally connected to one of the bucket members and pivotally connected to the head; links pivotally connected to the other bucket member and rigidly secured to the heads; sheaves in said pockets of the head; a sheave pin in the opening in the head on which the sheaves are journaled; a power arm; a latch between the arm and bucket members at the pivotal connection; and a trip mechanism for the latch comprising a spring on the power arm and a spring engaging pad on the central block.

In a clam shell bucket, the combination of bucket members; a pivotal connection be- V 'ly mounted on one of the bucket members; a

latch mounted on the power arm; a hook connection between the latch and bucket members adjacent to the pivotal connection, said atch connection tending under load to disengage; a removable wearing block on the latch; a trip lever on the power arm operaton the latch, the engaging surfaces of the trip lever and latch tending to lock the trip lever against disengagement under pressure of the latch; a yielding thrust means between the trip lever and the head, said thrust means being brought into engagement with the closing of the bucket and throwing the trip lever upon a release of the load pressure; means for adjusting the trip lever relatively to the latch; and a cable connection extendin" between the head and the power arm.

4. In a clam shell bucket, the combination of bucket members; a pivotal connection between the members; a head; links extending from the head to the bucket members at points remote from the pivot; a power arm pivotally mounted on one of the bucket members; a latch mounted on the power arm; a hook connection between the latch and bucket members adjacent to the pivotal connection, said latch connection tending under load to disengage; a trip lever on the power arm operating on the latch, the engaging surfaces of the trip lever and latch tending to lock the trip lever against disengagement under pressure'of the latch; means for adjusting the trip lever relatively to the latch; and a cable connection extending between the head and the power arm.

In testimony whereof I have hereunto set my hand.

, GEORGE F. THOMPSON. 

